adaptations

Assessing The Planet’s Most Unique Birds | Earth Wise

January 11, 2023 By EarthWise Leave a Comment

Birds come in a huge variety of shapes, sizes and plumages. The physical attributes of birds are adaptations that have taken countless millennia to develop, and physical attributes are closely related to the roles birds play in their environment.

According to a new study led by researchers from the University College London in the U.K., bird species with extreme or uncommon combinations of traits have the highest risk of extinction. Losing these bird species and the unique roles they play in the environment, including seed dispersal, pollination and predation, could have severe consequences on the health of ecosystems.

In the study, which was recently published in the British Ecological Society journal Functional Ecology, the researchers analyzed the extinction risk and physical attributes of 99% of all living bird species. The research team used a dataset of measurements collected from living birds and museum specimens. The measurements included things like beak size and shape, and the length of wings, tails and legs. The researchers combined this data with extinction risk, and then ran simulations to see what would happen if the most threatened birds were to go extinct.

Some of the bird species that are both most unique and most threatened include the Christmas Frigatebird and the Bristle-thighed Curlew. Kiwis were excluded from the study because the researchers viewed them as extreme morphological outliers.

While most unique birds were also classified as threatened on the Red List, the research was unable to show what links uniqueness in birds to extinction risk

The research team warns that if more isn’t done to protect these threatened species and avoid extinctions, the functioning of ecosystems will be dramatically disrupted.

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Planet’s most unique birds at higher risk of extinction

Photo, posted June 25, 2012, courtesy of Kristine Sowl / USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Sea Urchins And Climate Change | Earth Wise

August 1, 2022 By EarthWise Leave a Comment

There is a thriving population of black sea urchins in bubbling volcanic vents off the coast of Ishia, a small island in the Gulf of Naples. The oceanic environment there is very acidic, high in carbon dioxide, and very warm. The environment represents a proxy for what is gradually happening to oceans around the world.

Researchers from the University of Sydney have determined that the ability of sea urchins to prosper in such an environment means that these animals, which are already abundant in the Mediterranean Sea are likely to spread further afield as oceans continue to warm and become more acidic. The Mediterranean Sea is warming 20% faster than the global average.

Sea urchins are already an environmental problem in many places around the world. When their numbers increase disproportionately, they decimate kelp forests and algae, leading to the demise of other species that depend on these things for food or shelter. The result is something called an urchin barren, which is a rocky, sandy, urchin-filled seafloor devoid of other life.

Urchin barrens are increasingly common in many places, including the east coast of Australia and the coastline in the Americas stretching from Nova Scotia to Chile.

In Australia, for example, sea urchin populations have multiplied, and their range has expanded considerably, overgrazing kelp and damaging abalone and lobster farms.

Tests run by the Sydney researchers found that it is difficult to stress sea urchins. They appear to tolerate conditions that other creatures simply cannot. The only real positive is that understanding the urchins’ remarkable survival abilities might offer insights into adaptations that other animals might need in order to survive as the oceans become warmer and more acidic.

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Colonising sea urchins can withstand hot, acidic seas

Photo, posted January 31, 2010, courtesy of Anna Barnett via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Skydiving Salamanders | Earth Wise

June 28, 2022 By EarthWise Leave a Comment

The redwoods of the California coast are the tallest trees in the world. They are typically a couple of hundred feet tall and the tallest rise to a height of as much as 380 feet. Scientists have been studying the unique world of the redwood forest canopy for years. There are multiple animals that actually live up there. In fact, some spend their entire lives at the top of a single tree.

Over the past 20 years, researchers have been climbing redwoods to observe, capture, and mark salamanders that live in the canopy. The most arboreal species, called the wandering salamander, is a four-inch-long creature what moves up and down the branches of a tree where it spends its entire life. The researchers discovered a remarkable ability for the little amphibian.

The salamander readily leaps from perches in the crowns of redwood trees and has the ability to easily maneuver in midair back to a trunk or branch before it plummets to the ground. When the salamanders were startled by climbing researchers, they simply leap from the canopy and find their way to another perch lower in the tree.

The salamanders assume a skydiving posture with their forelimbs splayed out and can steer themselves by pumping their tails up and down. They can flip themselves over if they end up upside down. They have an impressive level of control.

What is most remarkable is that the salamanders, apart from having slightly larger foot pads, look no different from other salamanders that aren’t skydivers. They have no skin flaps or other anatomical adaptations that would give them the ability to glide. The researchers hope to eventually figure out just how these creatures have become expert skydivers.

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Skydiving salamanders live in world’s tallest trees

Photo, posted August 5, 2010, courtesy of Benson Kua via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Narwhal Tusks And Stories Teeth Can Tell | Earth Wise

February 4, 2020 By EarthWise Leave a Comment

Teeth and particularly narwhal tusks are getting some unusual press recently when one of them was the weapon of choice to fend off the London Bridge attacker, which was a good choice according to Harvard dental researcher Dr. Martin Nweeia. Turns out that narwhal tusks have some pretty amazing physical features. They exhibit both extreme strength and flexibility at the same time. The narwhal is known as the unicorn of the sea, a pale-colored, medium-sized whale found in Arctic coastal waters and rivers. In males, the more prominent tooth grows into a sword like, spiral tusk up to 8.8 feet long.

Changes in the shape of teeth over time can tell us about climate change. Adaptations in horse teeth 55 million years ago from North America were observed and caused by changes in climate, favoring different food sources. The horses changed their diets from fruit to more favorable grasses and their teeth changed in response. For this same reason, the teeth of elephants adapting in different environments of Asia and Africa have different tooth forms. Both eat plants but Asian elephants, with more ridges on their teeth, eat larger amounts of grasses while African elephants, with wider spread ridges, eat more leaves.

Teeth have been used to link land mass theories like the Bering Land Strait Theory, hypothesizing that North America and Asia were once one land mass. The teeth shape and form of people on both sides of the Bering Land Bridge shared a common “mongoloid dentition” with unique features. And so, can the narwhal tusk tell us something about a changing Arctic? Scientists have discovered that the narwhal tusk is a giant sensory organ that is able to continually monitor its environment and has the ability to detect ice formation, and melt, both capabilities helpful for surviving in a changing Arctic.

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–Earth Wise acknowledges script contribution from Dr. Martin Nweeia of Harvard University.

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Fossil teeth reveal new facts about a mass extinction 260 million years ago

From the Horse’s Mouth: Teeth Reveal Evolution

Photo, posted April 3, 2019, courtesy of James St. John via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Widespread Local Extinctions

January 17, 2017 By EarthWise

Plants and animals have evolved over time to live in specific environmental niches. As the climate warms, parts of the ranges in which they live may no longer offer the conditions under which they can thrive. Species can respond to these changes in three ways: they can adapt to new conditions by undergoing niche shifts; they can relocate to better conditions, such as by moving to higher elevations or latitudes; or they can locally go extinct.